The present invention relates to a method for manufacturing a semiconductor device; and, more particularly, to the method for manufacturing an aluminum oxide for use in the semiconductor device by employing NH3 reactive gas to deposit an aluminum source and/or an oxygen source on a wafer.
As is well known, a semiconductor device has a higher degree of integration mainly by downsizing through micronization nowadays. However, there is still a demand for downsizing the area of the memory cell, under increased transistor and circuit speeds and improved reliability. Such demands for increased density, performance and reliability require formation of device features with high precision and miniaturization. To meet the demand, it is necessary to increase a capacitance of a capacitor and improve a gate dielectric film which is applied for a DRAM and a logic devices. In attempt to solve an above requirement, various researches have been advanced to employ the high dielectric materials for a capacitor thin film and a gate dielectric film.
In particular, among the high dielectric materials, aluminum oxide (Al2O3) is typically used for the capacitor thin film and the gate dielectric thin film because the aluminum oxide has good oxidation resistance property and thermal stability. Furthermore, it can be popularly used as a hydrogen barrier for preventing hydrogen diffusion.
Generally, the aluminum oxide film is formed by using a method such as an atomic layer deposition (ALD). In more detail, a manufacturing steps are as follows: setting a wafer in a chamber; heating up the wafer to 200xc2x0 C. to 450xc2x0 C.; supplying an aluminum source material into the chamber for 0.1 to 3 seconds; flowing N2 gas into the chamber or vacuum purging for sweeping off unreacted aluminum source material and by-product; supplying an oxygen source material into the chamber for 0.1 to 3 seconds; and flowing N2 gas into the chamber or vacuum purging for sweeping off unreacted oxygen source material and by-product, again. This is one cycle for depositing the aluminum oxide film. Thus, by repeating this cycle more and more, intended thickness of aluminum oxide film is obtained.
In conventional method for manufacturing aluminum oxide film in the semiconductor device, trimethyl aluminum (TMA, Al(CH3)3) or modified trimethyl aluminum (MTMA, Al(CH3)3N(CH2)5CH3) is used as the aluminum source material and vaporized water is usually used as the oxygen source material.
However, the conventional method has a drawback that a growth rate of the aluminum oxide is very slow so that productivity may decrease. And further, the aluminum oxide film formed by the conventional method may contain carbon particles therein due to use of an organic material such as TMA or MTMA, thereby an electrical property thereof being deteriorated.
It is, therefore, an object of the present invention to provide a method for manufacturing an aluminum oxide film for use in a semiconductor device by applying NH3 reactive gas for improving a growth rate of the aluminum oxide film.
It is another object of the present invention to provide a method for manufacturing a semiconductor device incorporating therein an aluminum oxide film by applying NH3 reactive gas for improving a growth rate of the aluminum oxide film.
In accordance with one aspect of the present invention, there is provided a method for manufacturing an aluminum oxide film for use in a semiconductor device, the method comprising the steps of: a) preparing a semiconductor substrate and setting the semiconductor substrate in a reaction chamber; b) supplying an aluminum source material and NH3 gas into the reaction chamber simultaneously for being absorbed on the semiconductor substrate; c) discharging unreacted MTMA or by-product by flowing nitrogen gas into the reaction chamber or vacuum purging; d) supplying an oxygen source material into the reaction chamber for being absorbed on the semiconductor substrate; and e) discharging unreacted oxygen source or by-product by flowing nitrogen gas into the reaction chamber or vacuum purging.
In accordance with another aspect of the present invention, there is provided a method for manufacturing an aluminum oxide film for use in a semiconductor device, the method comprising the steps of: a) preparing a semiconductor substrate and setting the semiconductor substrate in a reaction chamber; b) supplying an aluminum source material into the reaction chamber for being absorbed on the semiconductor substrate; c) discharging unreacted MTMA or by-product by flowing nitrogen gas into the reaction chamber or vacuum purging; d) supplying an oxygen source material and NH3 gas into the reaction chamber for being absorbed on the semiconductor substrate; and e) discharging unreacted oxygen source or by-product by flowing nitrogen gas into the reaction chamber or vacuum purging.
In accordance with still another aspect of the present invention, there is provided a method for manufacturing an aluminum oxide film for use in a semiconductor device, the method comprising the steps of: a) preparing a semiconductor substrate and setting the semiconductor substrate in a reaction chamber; b) supplying an aluminum source material and NH3 gas into the reaction chamber simultaneously for being absorbed on the semiconductor substrate; c) discharging unreacted MTMA or by-product by flowing nitrogen gas into the reaction chamber or vacuum purging; d) supplying an oxygen source material and NH3 gas into the reaction chamber for being absorbed on the semiconductor substrate; and e) discharging unreacted oxygen source or by-product by flowing nitrogen gas into the reaction chamber or vacuum purging.
In accordance with further still another aspect of the present invention, there is provided a method for manufacturing a semiconductor device, the method comprising the steps of: a) preparing an active matrix provided with a substrate, isolation regions, gate line, gate oxide and a first insulating layer; b) forming a buffer layer and a first conductive layer on the active matrix subsequently; c) forming a dielectric layer of aluminum oxide (Al2O3) on the first conductive layer using an ALD technique, by supplying NH3 reactive gas with an aluminum source and/or an oxygen source; d) forming a second conductive layer on the dielectric layer and patterning the second conductive layer, the dielectric layer, the first conductive layer and the buffer layer, thereby obtaining a capacitor structure; e) forming a hydrogen barrier layer on the capacitor structure; f) forming a bit line and a local interconnection after depositing a second insulating layer; g) forming a passivation layer on entire surface.